Root canals are performed if the nerve of the tooth has been affected by either decay (cavity) or trauma (an accident that involved a blow to the face, tooth, or jaw and which has resulted in damage to the nerve of the tooth). A root canal is a procedure in which the inside of the tooth is cleaned and filled with a filling material. This closes and seals the space occupied by the nerve and blood supply that was once inside the tooth. Once a root canal is successfully performed, the tooth will no longer have sensitivity or pain and will be fully functional. A crown is highly recommended following a root canal for support and to prevent fractures/cracks.